The HIV ‘failure cascade’: low-resourced settings and the last ‘90’

04 September 2017

HIV programmes must develop strategies and allocate resources for people who enter the ‘failure care cascade’ – or risk jeopardising the important gains already made on HIV treatment.

As more people access lifesaving HIV treatment under a 'treat all' approach, the potential for gaps along the treatment cascade will increase. Indeed, it is thought that some 15% of patients on first-line antiretroviral treatment (ART) in resource-limited settings are unable to achieve viral suppression, the ultimate aim of HIV treatment programming.

A recent study from rural Lesotho analysed the experiences of those eligible for the ‘failure cascade’ – referring to individuals who had only achieved two of UNAIDS 90-90-90 targets. They have tested for HIV and accessed long-term antiretroviral treatment (ART), but they are unable achieve ‘the third 90’, viral suppression.

Despite the World Health Organization recommending a series of steps to address unsuppressed viral loads – consisting of enhanced adherence counselling (EAC), repetition of viral load testing (VL) and a switch to second-line ART – this ‘failure cascade’ appears to be rarely assessed or reported upon.

To address this, researchers evaluated the treatment of adults (aged 16 and over) on first-line ART attending 10 nurse-led facilities in rural Lesotho, a country with adult HIV prevalence of 25%.

Around 1,500 of facility patients received a first-time viral load test in June 2014, of whom 138 (8.8%) were not virally suppressed. Of these, less than half (41%) were in care and had a suppressed viral load after 18 months, 27% were in care but had an unsuppressed viral load and 33% were either lost-to-follow up, dead, transferred to another clinic or without a documented viral load test.

The study found substantial numbers of patients were lost at each step of the ‘failure cascade’. Of the original 138 virally unsuppressed patients, 124 (90%) attended EAC and 116 (84%) had follow-up viral load testing, meaning 22 patients were lost between the first and second viral load test.

Only two factors were significantly associated with being retained in care and virally suppressed: achieving re-suppression after EAC and being switched to second-line ART. No other association relating to socio-demographic variables, treatment history, viral resistance and viral re-suppression was found. This underlines the importance of timely adherence interventions and switching to second-line regimes should first-line fail.

The reason why participants were unable to achieve viral suppression or re-suppression may be attributed in part to a fragile and under resourced healthcare system. In addition, despite the health facility being informed about which patients qualified for second-line ART, more than a quarter did not benefit from such a switch.

One likely driver is that nurses were hesitant to switch a patient to a regimen with which they were personally unfamiliar. As a result, in countries where a high degree of task-shifting and decentralisation means nurses are responsible for making decisions about ART, training nurses on the diagnosis and management of treatment failure must become a priority.

The publication of this research is timely. The study’s authors highlight how, along with the massive scale-up of ART coverage, the number of people failing to suppress HIV while taking ART is expected to rise and, along with it, drug resistant HIV. In addition, the intended rollout of viral load monitoring will identify more people whose current treatment has failed. Yet none of the 10 targets outlined in UNAIDS’ current strategy specifically address the better management of patients with unsuccessful treatment – be it for reasons of poor adherence or HIV resistance.

HIV programmes must develop strategies and allocate resources for people who enter the ‘failure care cascade’ – or risk jeopardising the important gains already made on HIV treatment.